1. Field of the Invention
The invention relates to a data rewriting support system and a data rewriting support method for a vehicle control apparatus, in which data such as control programs and control data used to control the vehicle control apparatus are rewritten (reprogrammed) via a vehicle network.
2. Description of Related Art
In recent years, automobiles and other vehicles are equipped with many vehicle control apparatuses, such as an electronic control unit (ECU) that controls various in-vehicle devices such as an engine and a brake, meters that display various conditions of the vehicle, and ECUs that control auxiliary devices such as doors and air conditioners. These vehicle control apparatuses are connected by a vehicle network (an “in-vehicle LAN”) to be capable of mutual communication. When control programs, control data, and so on need to be updated (when data rewriting is required), the vehicle control apparatuses often exchange rewriting data via the in-vehicle LAN.
Data rewriting (reprogramming) must be performed on the vehicle control apparatus via the in-vehicle LAN so that control executed originally by the vehicle control apparatus is not affected. Therefore, in a system described in Japanese Patent Application Publication No. 2009-110528 (JP 2009-110528), for example, rewriting processing is executed in relation to an in-vehicle program of a vehicle when the vehicle is inoperative. By performing data rewriting while the vehicle is inoperative in this manner, a load exerted during the data rewriting does not affect vehicle travel.
Recently, attempts have been made to develop a system which enables the rewriting data to be downloaded to the vehicle from a management center through wireless communication so that data rewriting (reprogramming) using the downloaded data can be executed regardless of the condition of the vehicle.
In another conventional device such as that described in Japanese Patent Application Publication No. 2004-38616 (JP 2004-38616), for example, an operating condition such as a power supply to a reception apparatus to be subjected to an automatic software update is monitored, and a schedule for distributing new software for the automatic software update is determined on the basis of a monitoring result. However, even if the reception apparatus is in an operating condition enabling reception of the new software, the load on the network itself may increase when the new software is transmitted, and as a result, the exchange of data and so on between other apparatuses using the network may be impaired.